wifi: rsi: fix heap OOB write on key removal

From: Tianchu Chen <[email protected]>

When a key is removed (data == NULL), rsi_hal_load_key() runs:

	memset(&set_key[FRAME_DESC_SZ], 0, frame_len - FRAME_DESC_SZ);

set_key is a struct rsi_set_key *, so the subscript is scaled by sizeof(struct rsi_set_key) (160 bytes): &set_key[FRAME_DESC_SZ] is skb->data + 2560, and the memset writes 144 zero bytes starting 2.4KB past the end of the 160-byte skb data buffer, corrupting unrelated heap objects. The intended byte offset would have been (u8 *)set_key + FRAME_DESC_SZ.

The write fires on every DISABLE_KEY callback, so plain disconnects, roams and interface teardowns trigger it on real networks.

The memset is redundant: the whole buffer is zeroed right after allocation, so the frame sent to the device is byte-identical without it. Drop the else branch; normal operation is unaffected.

Discovered by Atuin - Automated Vulnerability Discovery Engine.

---
 drivers/net/wireless/rsi/rsi_91x_mgmt.c | 2 --
 1 file changed, 2 deletions(-)

index bb167f03367bf..d9dcbb2553176 100644
@@ -852,8 +852,6 @@ int rsi_hal_load_key(struct rsi_common *common,
 			memcpy(set_key->tx_mic_key, &data[16], 8);
 			memcpy(set_key->rx_mic_key, &data[24], 8);
 		}
-	} else {
-		memset(&set_key[FRAME_DESC_SZ], 0, frame_len - FRAME_DESC_SZ);
 	}
 
 	skb_put(skb, frame_len);

2.51.0